Knife-blade switch



A. H. TRUMBULL AND T. A. BOTH.

KNIFE BLADE swncH.

APPLICATION F'ILED JULY A11918- 1,354,525, Patented Oct. 5, 1920.

2 SHEETS-SHEET l.

A. H. TRUMBULL AND T. A. BOTH.

' KNIFE BLADE swlcH.l

APPLICATION FILED JULY l5, 1918.

.1,354,525 l Patented Oct. 5, 1920.

2 SHEETS-SHEET 2.

INVENTORS UNITED STATES EPATENT OFFICE.

.ALEXANDER H. TRUMBULL AND TONJESA. BOTH, OF STRATFORD, CONNECTICUT, ASSIGNORS TO V'THE CONNECTICUT ELECTRIC MANUFACTURING COMPANY, A

CORPORATION OF CONNECTICUT.

KNIFE-BLADE SWITCH.

To all whom t may con-cem.:

Be it known that we, ALEXANDER H. TRUMBULL and Tovans A. BOTH, citizens of the United States, residing at Stratford, county of F airfield, State of Connecticut, have invented an Improvement in Knife Blade Switches; of whichthe following is a specification. 'Y

This invention has for, its object to produce a knife blade switcliwhich has lbeen entirely reorganized and reconstructed in order to overcome objections that have been found to exist in all switches of t-his type now upon the niarket, and to provide a switch which shall be relatively inexpensive, extremely durable, easily adaptable to feed wires leading in from-above or below, which shall have a. quick break and shall provide the maximum of safety when required to carry a current of highvoltage.

Vith these and other objects in view we have devised the novel switch of which the following description Vin connection Ywith the accompanying dra-wingsris a specihcation,

reference numerals 'cing used to indicate the several parts.

Figure 1 is a plan view, the parts being in the circuit closing'po'sition; Y

Fig. 2 a side elevation corresponding therewith Y v Fig. 3 a section on the line 3 3 in Fig. 1, looking in the direction of the arrows;

Fig. 4 a perspective view of parts disassembled, illustrating our novel inode of connecting the blades tothe cross bar;

Fig. 5 a partial sideelevation showing the contact blades in a position instant before the circuit is opened;Y y

Fign 6 a perspective view of parts -disase seinbled, ill istrating the construction-of one of the auxiliary cont-act blades;

F 7 a. perspective view of' parts disas-A seinbled, illustrating our novelinode ofcounecting' the bladeslto the jaws; and V Fig. 8 is ar pla-n view illustrating slight changes in the details of construction.

10 denotes the base, 11 binding screws for the feed wires," `12 bindin screws for the circuit wires, 13 the jaws or posts. 14 the blades, 15 the auXiliary blades. V16 the cross bar to which the blades are attached, `17 the fuses and 18 the fuse clips.

In inost States it is required that the fuses Abe `located between the feed wires and the Contact jaws.

Specification of Letters Patent.

Patented Oct. 5, 1920.

serial No. 244,940.

tant so far as the present invention is concerned. In all States, however, it is required that the blades swing downward in opening the circuit. This is in order to prevent accidental closing of the circuit which lmight result` if the blades could drop to .the 'circuit closing position, the requirement being for a full upward swing' of the blades `in order to vclose the circuit. As the leading in or feed )osts as connected to the circuit bindin'o C screws 12 by strips 21.

lVhile it should be understood that the eleinents indicated by 13 are adapted to serve either as contact j aws cr as blade carrying posts, we shall for convenience in description refer to them as jaws. Four pairs of jaws are required, each pair being forined fromV a strip of metal bent at right angles on opposite sides of its midlengtlu the two jaws being' then bent obliquely toward each other and then parallel. the upper end of each jaw on the side toward theopposite pair of jaws, being caused to Hare outward slightly for convenience in making lcontact with the blades. The jaws are .attached to the base by screws 22.

The novelty of the jaws is comprised in the tension device. The tension devicecrdinarily used consists of a bolt, Ipassing through the jawsvand provided with a nut and spring` washer, and when the blades are reversed these parts'are transferred to the other set of jaws.' An important feature of our invention is tofprovide a permanent tension device in each post or pair of jaws,Y which' Vwill lea-ve the jaws `free to ada-pt themselves tothe blades and always" provide a springv contact. .This is av great improve-V ment on the tension devices heretofore in use and moreover costs little, requires no shifting of parts and isnot in the way whenthe blades` are reversed and the parts that previf ously served as Contact jaws are utilized as blade carrying posts. This result we accomplish by means of spring tongues 23 which are cut out from metal of the jaws and are provided with a cross connection 50, as a rivet or set screw extending between the tongues. Vhere rivets are used, as in Fig. 5, the rivets are of course headed at each end, one end only being shown. There set screws are used, as in Figs. 2 and 3, the set screws pass freely through one tongue and have `threaded engagement with the other, so that if required the tension ina-y be adjusted at any time. i Ordinarily, however, no adjustment of the tension is required when the blades are reversed, or under the ordinary conditions of use. The tongues are made suiliciently long to provide ample resilience and at their sides and one end are completely detached from the jaws, the sepa `ating cuts being made wide enough to prevent any contact between the tongues and the sur rounding walls of metal.

The blades aie detachably connected to the set of jaws serving` as posts in a novel inanner whichpermits quick attachment and detachment and 'without the use of screws. rlhe jaws are provided with holes 24- and the attaching end of each blade with a hole 25. The end of each blade is placed between a pair ofV jaws with the holes in alineincnt. A pin 30, having a sliding fit, is passed through the holes in the blade and the jaw, and is retained in place by a clip of' peculiar construction. This clip, see F ig. 7, is made of spring metal and consists of spring arms 2G which are adapted to clasp the blade, see Figs. l and 2. VEach of the spring arms has extending therefrom another spring arm 2?. The free end of each spring arm 27 is provided with a head 28 at the center of which is a shallow cup 29. The inner concave faces of these cups engage the ends of the pin and retain it in place. The edges of the cups bear against the outer lraces of the jaws and hold them against the blades with sufficient ypressure to retain the blades in any position' in which they may be placed. The clip, however, may be readily slipped oilV andon when it is required to reverse the blades.

lThe free ends of the blades in all switches f this type are connected by a cross piece which is usually made of fiber or molded to the required shape. Molded cross pieces are brittle and are easily broken unless made unreasonably large and unless made of eX- pensive mater'al frequently soften and warp when'a poor contact is made. Another ob jection to solid cross bars is that the screws or rivets by which they are connected to the blade are exposed and are live parts when the circuit is closed. The result is that the operator may get a shock in operat#V ing the switch unless great care is used, or

vided at their' aw'engaging ends with ears 32 adapted to pass through the slots and into the tubes, the ears being provided with shoulders 33 which engage the ends oi the slots. 84e denotes internally threaded plugs which are driven into the ends of the tubes past the slots with a drive lit. The ears are provided with holes Screws 36 pass through these holes without threaded engagement and are turned into engagement with the threaded holes in the plugs, thus .locking the blades and the cross bar rigidly togethervwith a wholly concealed and insulated connection. This cross bai' may con" tact with the ends ofthe aws in the circuit closing movement and serve as a stop ttor the movement of the blades, and may also con-- tact with the lower fuse clipsV in the open circuit position, 37 denotes a knob or handle which is ordinarily provided 'but is not necessary as the cross piece provides a smooth and safe grip for the hand.

In order to insure a quick break, we provide the auxiliary blades l5, which are et' novelfconstruction and are attached to the blades in a novel manner, the spring being wholly concealed. Each auxiliai'y blade is blanked out from sheet metal and folded upon itself. The exact thickness of the metal used is immaterial but as the auxiliary blades must be 01"' uniform thickness 'itl the blades we preferably use lorthe auniliary bladeis secured by a pivot pin 39 which passes through holes in the and the blade. Between the ears is a socket Ll-U which the spring 4l is housed. This s is a coll carried by a pini2, which passes through the walls ot the socket, and is provided with extended ends oiie oi which i u 'V n bears against the under side oi the blade and the other against the bottoni of the soc-liet in the auxiliary blade, the normal action oi the spring being to retain the top oi the auxiliary blade in close contact with the under side of the corresponding blade lll., compare Figs. .fl and 5. Y

ln moving the blades to the circuit clesing position, the auxiliary blades of courzie Vtake the load first and pass it ,to theV blades.

As the meeting faces of the blades andthe lauxiliary blades are `in. closecont'act, -the V.passage ofthe current is not limited to the hinge Vconnection between the blades. ln opening or breaking the circuit the action is as shown in Fig. 5,. The blades will first passent of engagement with the jaws'leaving theauxiliary blades, however, in engagement with the jaws. rhe circuit will remain closed until the ends A ofthe auxiliary blades, through the upward vmovement Y the Vauxiliary bladesout of engagement'with the jaws, and the springs will .cause the auxiliary blades to break the circuit with a snap, the auxiliary blades `instantly returningt'o their normal position, in close contact with the blades, as in Fig. 4.

The form illustrated in Fig. 8 differs .only

' in details of construction. The clips which retain thev blade pins in yplaceand pressthe arms ofthe aws against the bladesiare carried by the jaws instead of by the blades.

v .In this form we .use a U-'shaped clip, Acoin- Vthe tubular insulatingfcross piece differs in prising simply .arms 45 .provided at their freeeiids with heads 46 which correspond in every'respect with the heads 28 and cups 29 of the'other form, the additional spring Varmsibyvwhichtheheads are carried in the other form being dispensed with.V The attachment of the free-ends of the blades to that the cross piece is attached to the ends 'of the blades' and lies inapproximately the .same planel as theblades, instead of ,being secured to the tops. of the blades and'lying above them, le have also shown the plugs 48 within the cross piece as lying outside the ears 49. at the ends of the blade instead ofV on the inner sideV of the ears as in gtheother forni. In theA present form the screws i7 pass throughthe plugs without threaded engagement and have threaded engagement with the ears. The knob or handle in this form is shown` as attachedfin such a manner as to project forward from the cross piece, instead vof. lying above the crossv piece 'as in the other form. 1 Y

Having thus described our invention, we claim: 7

l. In a switch of the character described, two sets of jaws, each set consisting of two pairs ofj'aws provided with means enabling them to serve either as blade carrying posts or as contact jaws, each pair of jaws being formed4 from -a'strip of metal Abent at rig-ht angles at oppositesides of its midlength, the

Yjaws being thenbent obliquely toward each other Vand then parallel, each jaw having a tongue cut out from the parallel portion thereof, a .cross connection in each pair of tongues, andblades pivotally connected to one set of jaws and adapted to engage the other set to close the circuit. i

2. In a switch of the character described,

two sets of jaws formed from strips of sheet Vmetal bent toshape, each set consisting of two pairs of jaws provided with means enabling them to serve either as blade carrying posts or as contact jaws, blades pivotally connected to one set of jaws and adapted to engage the other set to close the circuit, andeach pair of jaws being provided with tongues cut out from the metal thereof and a cross connection engaging the tongues, to provide a tension for the jaws.

3. Jaws of the character described formed from a strip of sheet metal bent to shape, each jaw being provided with a tongue cut out from the metal thereof, and a cioss Vconnection engaging the tongues, substantially as described for .the purpose specified.

at, In .a switch of the character described,

4two pairsof jaws, each pair being provided vwith meansenabling it to serve either as a blade carrying post or as contact aws, holes vin Valiiiement in each pair of jaws, a blade havingat its attachingrr end a corresponding holea pin adapted to engage said holes and a spring clip having heads which engage the jaws and retain the pin in place.

5. ln a switch of the character described,

' two pairs of jaws, each pairY being provided with means enabling it to serve either as a blade carrying rpost or @ascontact jaws, av blade, a pin extending through one pair of jaws and the blade, and a detachable spring clip for retaining the pin in place.

6. In a switch of the character described, two pairs of jaws, each pair being provided withineans Yenabling itto serve either as a` Vblade carrying post or as contact jaws, a

blade, a pin extending through one pair of jaws and the blade, 'and a detachable spring clip for retaining the pin in place, saidclip being providedrwith means for attachment to the blade.

7. in a switch of the character described,

Ytwo pairs of aws, each pair being provided with means enabling it to serve either as a blade carrying post or Vas contact jaws, a blade, a loose pin extending through one pair of jaws Vvand the blade, and a detachable iio with means enabling it to serve either as a l blade. carrying post or as contact jaws, a

blade, a pin extending through-'one pair of jaws and the blade, and av detachablespring clip adapted to engage the jaws and having heads provided with cups which receive the ends ofthe pin, said clip being provided with means for attachment to the blade.

9.` In aiswitch of the character described, two pairs of jaws, each pair being provided with means enabling it to serve either as a blade carrying post or as Contact jaws, a blade, a pin extending through one pair of jaws and the bladea detachable clip having spring arms which clasp thev blade and spring arms extending from the blade clasping arms and provided with heads which bear upon the jaws and retain the pin in place.

10. In a switch of the character described, two pairs of jaws, each pair being provided with means enabling it to serve as a blade carrying post or as contact jaws, each jaw being provided with a tongue cut outl from the metal thereof, a cross connection engaging the tongues to provide tension for the jaws,a blade, a loose pin passing through one pair of jaws and the blade, and detachable Ineans for retaining the pin in place.

11. In a switch of the character described, two pairs of jaws, each pair being provided with means enabling it to serve as a blade carrying post or as contact jaws, each jaw being provided with a tongue'cut out from the metalthereof, a cross connection engaging the tongues to provide tension for the jaws, a blade, a pin passing through one pair of jaws land the blade, and a detachable clip having spring arms clasping the blade and other spring arms which engage the jaws and retain the pin inplace.

12. In a switch of the character described, contact blades provided with ears, and a tubular insulating cross bar having slots which receive the ears, and means within the tube for attaching the blades thereto.

13. In a switch of the character described, contact blades having ears, a tubular insulating cross bar having slots which receive the ears, plugs driven into the tube, and screws within the tube which engage the ears and plugs and lock the blades to the cross bar.

14. In a switch of the character described, contact blades having ears provided with shoulders, a tubular insulating cross bar having slots which receive the ears, the ends of the slots being engaged by the shoulders, plugs in the tube, and screws engaging the ears and the plugs for the purpose set forth.

15. A switch of the character described comprising two sets of jaws, each set consisting of two pairs of jaws, each set being provided with means enabling it to serve as blade .carrying posts or as contact jaws, blades pivotally connected to one set of jaws, andan insulating cross bar having an insulated connection to the blades Vand adapted a stop in the circuit closing position.

16. A switch of the character described A comprising two sets of jaws, each set consisting of two pairs of jaws, blades, pins passing through each blade and a pair of jaws, spring clips by which the pins are retained in place, and an insulating tubular cross bar having an insulated connection to the other endsof the blades.

17. A switch of the character described comprising two sets of jaws, each set consisting of two pairs of jaws, blades, pins passing through each blade and a pair of jaws, spring clips claspingv the blades and having spring arms which retainthe pins in place, and an insulating cross bar having an insulated connection to the other ends of the blades.

18. A switch of the character described comprising two sets of jaws, each set consisting of two pairs of jaws, each pair of jaws being provided with tongues cut out from the metal thereof, set screws engaging the tongues for the purpose set forth, blades, means Vfor detachably connecting the blades to one set of jaws, and an insulating tubular cross bar having an insulated'connection to the other ends of the blades.,

19. A switch of the character y describedl comprising two sets of jaws, each set consisting of two pairs of jaws, each pair of jaws being provided with tongues cut out fromV 'the metal thereof, set screws engaging the tongues for the purpose set forth, blades, pins passing through each. blade and a pair of jaws, spring clips carried by the blades 'and having spring arms engaging the jaws to retain the pins in place, and an insulating tubular cross bar having an insulated connection to the other ends of the blades.

21. In a switch of the character described, a blade, an auxiliary blade blanked out from sheet metal and folded upon itself, the attaching end of the auxiliary blade being provided with ears adapted to lie on opposite sides of the blade and being pivoted to the blade, and a spring housed in the auxiliary blade and acting to retain the auxiliary blade in Contact with the blade.

22. In a' switch of the character described, a blade, an auxiliary blade blanlred out from sheet metal and folded upon itself, the attaching end of the auxiliary blade being prcvided with a socket and with ears which lie on opposite sides of the blade and are pivoted thereto, and a spring housed in the auxiliary blade and acting to retain the auxiliary blade in contact with the blade.

23. In a switch of the character described, a blade, an auxiliary blade blanked out-from sheet metal and folded upon itself, the attaching end of the auxiliary blade being provided with a socket and with ears which lic on opposite sides of the blade and are pivoted thereto, aV spring comprising a coil having extended ends, and a pin passing through the coil andthe walls of the socket, the ends of the spring bearing respectively against the under side of the blade andthe bottom of the socket, whereby the auxiliary blade is retained in contact with the blade.

2a. A switch-of the character described comprising a blade, an auxiliary blade formed from thinner metal than the blade and folded upon itself to uniform thickness with the blade, the auxiliary blade being provided with a socket and'ears which are pivoted to the blade, and a spring in the socket whereby the auxiliary blade is retained'in contact with the blade.

25.- Aswitch of the character described comprising a blade, an auxiliary blade pivoted thereto, and a spring socketed in the auxiliary blade for normally retaining it in contact with the blade.

26. A switch of the character described comprising a blade, an auxiliary blade having ears pivoted. on opposite sides of the blade and a socket between the ears, the pivoted end of the auxiliary blade serving asa stop to limit the separation of the blades, and a spring in the socket acting to retain the edges of the blades in Contact.

27. In a switch of the character described. two sets of jaws formed from strips of sheet metal bent to shape, each set consisting of two pairs of jaws provided with means enabling them to serve either as blade carrying posts or as contact jaws, blades pivoted to one set of aws, auxiliary blades pivoted to the blades, and springs socketed in the auxiliary blades for retaining them in contact with the blades.

28. In a switch of the character described, two sets of jaws formed from strips of sheet ymetal bent to shape, each set consisting of two pairs of jaws provided with means enabling them to serve either as blade carrying posts or as contact jaws, a tension device in each pair of jaws comprising spring tongues cut out from the metal thereof and a set screw engaging the tongues, blades, a pin extending through each pair of jaws and a blade, detachable spring clips for retaining the pins in place, auxiliary blades pivoted to the blades, and springs socketed in the auxiliary blades for retaining thc edges of the auxiliary blades and the blades in contact.

29. In a switch of the character described, two sets of jaws formed from strips of sheet metal Ybent to shape,.each set consisting of two pairs of jaws providedwith means enabling them to serve either as blade carrying posts or as contact jaws, a tension device in each pair of jaws comprising spring tongues cut out from the metal thereof and a set screw engaging the tongues, blades, a pin extending through each pair of jaws and a blade, detachable spring clips for retaining the pins Ain place, auxiliary blades pivoted to the blades, springs socketed in the auxiliary blades for retaining the edges of the Yauxiliary blades and the blades in contact, an insulating tubular cross bar, and insulated means for connecting the blades to the cross bar.

80. In a switch of the character described, two sets of aws formed from strips of sheet metal bent to shape, each set consisting of two pairs of jaws provided with means en-V abling them to serve either as blade carrying posts or as contact jaws, a tension device in each pair of jaws comprising spring tongues cut out from the metal thereof and a set screw engaging the tongues, blades, a

pin extending through each pair of jaws and a blade, clips having spring arms which clasp the blades and other spring arms having heads which retain the pins in place, auxiliary blades pivoted to the blades, and springs socketed in the auxiliary blades for retaining the edges of the auxiliary blades and the blades in contact.

31, In a switch of the character described, two sets of aws formed from strips of sheet metal bent to shape, each set consisting of two pairs of jaws provided with means enabling them to serve either as blade carrying posts or as contact jaws, a tension device in each pairof jaws comprising spring tongues cut out yfrom the metal thereof and a set screw engaging the tongues, blades, a pin extending' through each pair of jaws and a blade, clips having spring arms which clasp the blades and other spring arms having heads which retain the pins in place, auxiliary blades pivoted to the blades, springs socketed in the auxiliary bla-des for retaining the edges of the auxiliary blades and the blades in contact, ears extending from the blades, a tubular insulating cross bar having slots which receive theears and means within the cross bar for attaching the cross bar to the blades.

In testimony whereof we affix our signatures.

ALEXANDER H. TRUMBULL.V TONJES A. BOTH. 

